Question

when triglycerides are ingested, they are broken down into fatty acids and glycerol in the small intestine. these smaller molecules are able to cross the cell membrane and enter a cell. once inside a cell, fatty acids and glycerol are recombined into a triglyceride. triglycerides are then stored in fat tissue until they are needed for energy.

chemical structure of stearin, a triglyceride

select the true statements.

• in cells, fatty acid and glycerol molecules are combined to make triglycerides.
• triglycerides from food are broken down in the stomach.
• triglycerides are stored until they are needed for energy.
• triglycerides travel across cell membranes.

Explanation:

1. For "In cells, fatty acid and glycerol molecules are combined to make triglycerides": The text says "Once inside a cell, fatty acids and glycerol are recombined into a triglyceride", so this is true.
2. For "Triglycerides from food are broken down in the stomach": The text states breakdown occurs in the small intestine, not stomach, so this is false.
3. For "Triglycerides are stored until they are needed for energy": The text says "Triglycerides are then stored in fat tissue until they are needed for energy", so this is true.
4. For "Triglycerides travel across cell membranes": The text says "These smaller molecules (fatty acids and glycerol) are able to cross the cell membrane", not triglycerides directly, so this is false.

So the true statements are:

• In cells, fatty acid and glycerol molecules are combined to make triglycerides.
• Triglycerides are stored until they are needed for energy.

Answer:

• In cells, fatty acid and glycerol molecules are combined to make triglycerides.
• Triglycerides are stored until they are needed for energy.